Distributor for used in a method of casting molten metal into a metal ingot are often used in the aluminium industry where aluminium, as the molten metal, is cast into ingots of a desired shape. The distributor is positioned inside a casting mould and molten metal is fed, mostly through a casting pipe, into the distributor. The function of the distributor is to control the velocity and recirculation and the solidification processes of the molten metal in the mould with the object to obtain a homogeneous ingot.
The most common form of a distributor is a bag in the form of a box made of woven glass cloth. The bottom and walls are made of glass cloth, which is because of the density with which it is woven, impermeable for the molten metal.
The various apertures are covered with open woven glass cloth, which acts as a filter to prevent inclusions from entering into the ingot.
A problem with the known distributor in the form of a flexible bag is that, because of its flexibility, the flow of molten metal from the distributor into the mould is difficult to control. In particular, macro-segregation wherein the concentrations of the additives and alloying elements change over the cross section of the ingot is a problem. Macro-segregation is caused by insufficient stirring of the hot metal in the mould, through insufficient control of the flow through the various apertures in the distributor and the unstable shape of the bag during casting.
Another problem with the flexible bag is that it can only be used for casting a single ingot after which the bag has to be discarded. This leads to high costs and waste, which is unwanted from an environmental point of view.